Hi Janice
I've been having a good hunt round this morning on this one. Your Oliver is EXTREMELY elusive, isn't he
Does the marriage certificate give an age for Oliver? Reason for asking is that there's an Oliver Thomas (b abt 1874 in Bream) living in 1891 as an adopted son of George and Esther
Smith 
in West Dean. Ref RG12 4339 Folio 33 Page 19.
I know - it gets worse! That family is interesting, not least because of the apparent;y huge age gap between George and Esther. If you look them up in Ancestry, be prepared for the fact that the index links to the wrong page (22) so you have to go back three pages to find the family.
I did wonder if Oliver's Mum had been married several times and perhaps not married Oliver's Dad? I've got a number of families where the child of a previous marriage (or an illegitimate one) takes the name of the mother's subsequent husband and the sometimes reverts on their marriage certificate and sometimes not......
I couldn't find a birth index reference to any Oliver born in an appropriate registration district in the 1870s, so I think the best bet is to hope that the family weren't non-conformists and that Oliver was baptised in Bream.
I think there's a website with transcriptions of Forest of Dean records on but I can't find it at the moment - will add it when I do. Otherwise, someone might have a look at the record office for you....
Angela
